"As we do when confronted by moments of darkness and challenge, we must now come together as one American family," Obama said, according to the AP. "All of us must have the people of Aurora in our thoughts and prayers as they confront the loss of family, friends, and neighbors."

Republican presidential candidate Mitt Romney and his wife Ann said they were "deeply saddened by the news of the senseless violence," the AP reported.

UPDATE: Comments from men and women who were at the theater when the gunman opened fire are starting to roll in.

“There was this one guy on all fours crawling," Tate told CBS Denver. "There was this girl spitting up blood. There were bullet holes in some people’s backs, in some people’s arms. There was one guy who was just stripped down to his boxers. It looked like he had been shot in the back or something."

Watch CBS Denver's full interview with Tate:

Another man, who was sitting in Theater #9 when the violence started told CBS Denver "somebody kicked in the emergency exit and started throwing gas grenades and started shooting people at random."

Twitter is flooded with reactions to tragic shooting. Here is what people are saying: